Fluorescent lighting in an office

[jamminuk]

Hi all,

Replacing a 6ft fluorescent strip light in an office, took the old one down and put the new one up but the connections on the old one arn't the same as the new one bummer!!! There must be at least 4 sets of wires coming out the cieling, on the new fitting there is just the usual L N earth connector block, do i just put all live in L all neutral in N and earth in E, i know it may sound like a silly question but the other light seemed so much more complex. I know one must be the feed, the other a switch line and another the loop but just wanted confirmation.

Thanks

Ben

 

[Adam W]

I would imagine it's wired like a rose in a house.
Could you do that? Wire into a Klik (or similar) rose?

 

[telectrix]

time to dig the wagos out.

 

[jamminuk]

I would imagine it's wired like a rose in a house.

That's what i was thinking, the worst thing was i got called to an emergency so couldn't finish wiring it up, when i turned the power back on none of the other lights casme back on?? Ooops i'm thinking that must either be that because the neutrals wern't connected together creating a circuit or the bulbs on all the light blew because i just used the breaker to cut the power instead of switching the lights off at the switch?? not sure

 

[jamminuk]

time to dig the wagos out.

Wagos?

 

[telectrix]

connectors without screws.

be aware that the connector is not like a choc block don't put L and N in the same 1 !

the pic shows a wago for 5 N's. thet come in 2 way, 3 way, 4 way etc. just lever up cable in , lever down... done.

 

[Engineer54]

Good job Paul isn't around tonight!!! lol!!

 

[mogga]

CALL a qualified electrician as you dont seem to be Competant by asking the original question either that or you need to go back to college for a refresher

 

[malcolmsanford]

Is this in multicore or singles?

Is there an emergency lighting pack on the old fitting and the new one is just a standard?

Not being funny Jamminuk are you a sparks?

 

[jamminuk]

It's done in t+e, no emergency battary pack, just the connections on the old one was way different. I've not long been in the trade, done the college and have had some experience but i thought that was what this forum was for, advice?? thanks any way

 

[jeremy]

Advice (and opinion!) is what the forum is all about! Is there any chance of a photo of the wiring? if we can see what you can the advice will be that little bit more informed.

 

[Richard Burns]

Good important tip before taking down a fitting make a note of where all the wires are connected!
It can be very difficult to identify wiring afterwards especially is the person wiring it up has not correctly sleeved the cores.
The likely inputs you have (if there are 4 T&E) is one incoming LNE, two outgoing LNE to other lights, one (SL)LE if the lights are individually switched.
If the lights are not individually switched then it could be one incoming (SL)NE and three outgoing (SL)NE to three other lights.
If there are emergency lights present then they might need a permanent line as well as switched line and this could be carried around the whole set up but the permanent line would not connect to this light but otherwise would be similar to the first case.
Overall very difficult to say what you have without seeing it (and knowing how it was wired initially)
Very likely that without the correct wires joined at the light fitting that the other lights would not work, if they all do not work then this is probably the first light in the run, any that do work would be before this one in the string.

 

[jamminuk]

Thanks for taking the time to give advice, here's a pic that may help, probably not the best pic though. There is one yellow wire which can't be seen here either, the light blue one is also present atone of the switches so i'm guessing this is the switch line.

 

[Richard Burns]

Not immediately obvious from the photo, Unsurprisingly.
It looks like you have one 3+E and three 2+E but one of the 2+Es sheathing is not visible. It looks like the yellow from the 3+E is mixed up with the cpcs. Is the blue connected to the switch or just joined there (I would normally use blue as neutral on 3 core)?
One thing that may help is if you have a suspended ceiling or can see the wiring above the light see where the cables head toward i.e. other lights or light switch (not very much use if in a domestic type ceiling).
Check if there are any emergency lights in the office (there should be) as these will need line and switch line.
Could be LNE in (from MCB) and out (perhaps to EL) on two of the 2+E, the 3+E takes L to switch and SL back (along with NE) and the third 2+E caries SL on to the next light.

It is possible that you may have L SL N + E coming in on the 3+E (fed from the switch) then one 2+E is carrying permanent line to the emergency light and another carrying switched line to the emergency light both along with NE and the other 2+E is switched line to another light. But this would be a waste of cable and not very likely.

Probably your best best is to separate all the wires use a long lead from the light to the switch and the MCB and test continuity until you have identified the incoming and switched supplies, slow and tedious but you will get there in the end. Then test continuity from the light to the other lights (checking if you need permanent line) to identify the other cables.

Once identified link the loop cables with wagos and wire the rest in the block.

Lots of luck!